Currently Council has detailed information for soils mapped on the Wairau Plain and the lower Awatere Valley. For the rest of Marlborough we have very little or more often no soils information available.
An example is the Kaituna/Havelock district where there is no available information on important soil parameters such as water holding capacity, drainage, soil depth and permeability. This information is critical if we want to help landowners manage their soils for activities such as irrigation scheduling, effluent application, stock management etc.
Furthermore, a range of models such as Overseer, SPASMO and the Dairy Pond Calculator, which are increasingly being used by Council and industry, require accurate soils information to help predict things like nutrient losses from soils, water requirements and the suitability of soils for effluent application.
The aim of this project was therefore to describe, sample and analyse soils from representative sites in the Kaituna/Havelock and Linkwater districts. This information will be summarised into fact sheets and made available to landowners in the region and be available for incorporation of various models used by Council and industry to ensure the most efficient use and protection of our natural resources.
A series of soil auger observations were made across a range of sites in the Kaituna/Havelock and Linkwater districts to identify the dominant soil types. Nineteen soil profiles were described and top and subsoils sampled and analysed for a range of soil physical and chemical properties.
Three soil families were identified i.e. Koromiko, Manaroa and Kaituna soils which occupy different parts of the landscape. The Koromiko family of soils occurs on the lower land surfaces – on stream and river floodplains and low terraces. The Manaroa family occur on surfaces intermediate between the lower floodplains and remnant terrace and fan surface. The Kaituna soil occurs on terraces and fans that occur above the valley floor. A report summarising the results has been compiled.